opentelemetry-collector/internal/fanoutconsumer/logs.go

84 lines
2.8 KiB
Go

// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0
// Package fanoutconsumer contains implementations of Traces/Metrics/Logs consumers
// that fan out the data to multiple other consumers.
package fanoutconsumer // import "go.opentelemetry.io/collector/internal/fanoutconsumer"
import (
"context"
"go.uber.org/multierr"
"go.opentelemetry.io/collector/consumer"
"go.opentelemetry.io/collector/pdata/plog"
)
// NewLogs wraps multiple log consumers in a single one.
// It fans out the incoming data to all the consumers, and does smart routing:
// - Clones only to the consumer that needs to mutate the data.
// - If all consumers needs to mutate the data one will get the original mutable data.
func NewLogs(lcs []consumer.Logs) consumer.Logs {
// Don't wrap if there is only one non-mutating consumer.
if len(lcs) == 1 && !lcs[0].Capabilities().MutatesData {
return lcs[0]
}
lc := &logsConsumer{}
for i := 0; i < len(lcs); i++ {
if lcs[i].Capabilities().MutatesData {
lc.mutable = append(lc.mutable, lcs[i])
} else {
lc.readonly = append(lc.readonly, lcs[i])
}
}
return lc
}
type logsConsumer struct {
mutable []consumer.Logs
readonly []consumer.Logs
}
func (lsc *logsConsumer) Capabilities() consumer.Capabilities {
// If all consumers are mutating, then the original data will be passed to one of them.
return consumer.Capabilities{MutatesData: len(lsc.mutable) > 0 && len(lsc.readonly) == 0}
}
// ConsumeLogs exports the plog.Logs to all consumers wrapped by the current one.
func (lsc *logsConsumer) ConsumeLogs(ctx context.Context, ld plog.Logs) error {
var errs error
if len(lsc.mutable) > 0 {
// Clone the data before sending to all mutating consumers except the last one.
for i := 0; i < len(lsc.mutable)-1; i++ {
errs = multierr.Append(errs, lsc.mutable[i].ConsumeLogs(ctx, cloneLogs(ld)))
}
// Send data as is to the last mutating consumer only if there are no other non-mutating consumers and the
// data is mutable. Never share the same data between a mutating and a non-mutating consumer since the
// non-mutating consumer may process data async and the mutating consumer may change the data before that.
lastConsumer := lsc.mutable[len(lsc.mutable)-1]
if len(lsc.readonly) == 0 && !ld.IsReadOnly() {
errs = multierr.Append(errs, lastConsumer.ConsumeLogs(ctx, ld))
} else {
errs = multierr.Append(errs, lastConsumer.ConsumeLogs(ctx, cloneLogs(ld)))
}
}
// Mark the data as read-only if it will be sent to more than one read-only consumer.
if len(lsc.readonly) > 1 && !ld.IsReadOnly() {
ld.MarkReadOnly()
}
for _, lc := range lsc.readonly {
errs = multierr.Append(errs, lc.ConsumeLogs(ctx, ld))
}
return errs
}
func cloneLogs(ld plog.Logs) plog.Logs {
clonedLogs := plog.NewLogs()
ld.CopyTo(clonedLogs)
return clonedLogs
}